Toric-lens-grinding machine



R. H. AND R. J. BECK.

TORIC LENS GRINDING MACHINE. APPLICATION FlLED NOV. 13, I916.

Patented June 15, 1920.

4 SHEETSSHEET I.

R. H. AND R. J. BECK.

TORIC LENS GRINDING MACHINE.

APPLICATION FILED uoy. I3. 1916.

1,343,492. Patented Jun 15, 1920.

4 SHEETS-SHEET'Z.

ATTO R N EYS INVENTORS R. H. AND R. J. BECK.

TORIC LENS GRINDING MACHINE.

APPLICATION FILED NOV-13.1916.

I 1,343,492, Patented Julie, 15, 1920.

4 SHEETS-SHEET 4.

UNITED; STATES PATENT QFFIQE.

RUDOLPH H. BECK AND RUDOLPH J. BECK, 01" PHILADELPHIA, PENNSYLVANIA.

TORIC-LENS- GRINDING MACHINE.

Specification of Letters Patent.

Patented June 15, 1920.

Application filed November 13, 1916. Serial No. 131,005.

I '0 all whom it may concern:

Be it known that we, RUDOLPH H. Bnon and RUDoLrH J. BECK, both citizens of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Toric Lens-Grinding Machine, of which the following is a specification.

Our present invention relates to a grind ing machine which is especially adapted for the grinding of toric lenses.

Our invention comprehends a novel construction of a dis-synchronizer, whereby the grinding laps are caused to cooperate with tl e lenses in different paths during the grinding operation, in order to dis-synchronize the oscillating action of such laps.

It further comprehends a novel construe tion of a compensator, whereby each side of the lens will be properly ground irrespective of the foci of the lenses.

It further comprehends novel means for varying the length of stroke of the oscillating yoke and thereby of the grinding laps.

it further comprehends novel means for supporting the yoke, novel means for securing the grinding laps with respect to the yoke, novel lens blocks and securing means therefor, and novel means for adjusting and actuating the various parts of the mechanism.

()ther novel features of construction and advantage will hereinafter more clearly appear in the detailed description of our in vcntion and the appended claims.

For the pin-pose of illustrating our invention, we have shown in the accompanying drawings, a typical embodiment thereof, which is at present preferred by us, since the same will give in practice satisfactory and reliable results, although it is to be understood that the various instrumentalities of which our invention consists can be variously arranged and organized and that our invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described.

Figure 1 represents a front elevation of a toric lens grinding machine embodying our invention.

Fig. 2 represents an end elevation of our machine.

Fig. 3 represents a section 011 line 33 of Fig. 2.

Fig. 4 represents a perspective view of a dis-synchronizer, the parts being shown in spaced relationship.

Fig. 5 represents a section on line 55 of F 1g. 2, certain parts being omitted.

Fig. 6 represents a section on line 6-6 of Fig. 1.

Fig. 7 represents a section on line 7-7 of Fig. 6.

Fig. 8 represents an end elevation of the construction seen in Fig. 7.

Fig. 9 represents a section on line 9-4) of Fig. 1.

Fig. 10 represents a side elevation of a lens block and certain of its adjuncts.

Fig. 11 represents in side elevation 21 w ll known type of reversing mechanism.

Similar numerals of reference indicate corresponding parts in the figures.

Referring to the drawings 1 designates the standards of a lens grinding machine embodyingour invention, said standards supporting the cross-beams 2, to which are connected the journal bearings 3, in which latter is mounted the main driving shaft 4, which is adapted to be driven by any desired source of power.

For purpose of illustration, the driving shaft 4: is shown in 1 and 2 as pro vided with a pulley around which passes a driving belt 6, which is driven in any desired manner. The shaft 4-. has mounted thereon a gear 7 which meshes with a gear 8 mounted on a shaft 9. which is journaled in brackets 10. The shafts 9 and 4 each form a spindle which is adapted to carry a lens block. The shaft l has its outer end, as at 11, adapted to receive a lens block 12 which is secured in position between a collar 13 fixed on the shaft 4 and a kev 1% which its tightly in the hub of'the lens block and passes through an aperture 15 in the shaft 4, said key and aperture preferably having a polygonal shaped contour and the aperture being of greater length in cross section than the width of the key, so that the lens block will be maintained in proper relationship with respect to the collar 13 by means of a set screw 16 in threaded engagement with the drive shaft 4 and bearing against the key '14. The shaft 9 has mounted thereon in a similar manner a lens block 17. The lens block 17 is retained in position between a set collar 18 on the shaft 9 and a key 19 preferably of rectangular contour and passing through a rectangular shaped aperture 20 in the shaft 9.

21 designates a set screw in threaded engagement with the shaft 9 and bearing against the key 19 to maintain the lens block 17 in proper position. Each of the lens blocks are constructed in a similar manner, and the details of construction will be best understood by reference to Fig. 9. Each lens block consists of a hollow casting 22 having the hub portions 23, into which is driven a tubular bushing 24 in order to prevent any grinding material passing into the interior of the lens block. The outer periphery of the lens block is preferably smooth. and is covered with a coating of pitch or other adhesive material 25, on which the lenses 26 are secured, as will be understood by reference to Figs. 9 and 10.

The main driving shaft 4 has loosely mounted thereon a pulley 27, the hub of which is provided with a driving lug 28, which forms a segment of a circle and preferably one-quarter of a circle, and is provided with the converging or angularly inclined faces 29. 3O designates a set collar fixed to the shaft 4 in any desired manner and provided with a driving lug 31. The driving lug 31 is approximately 180 and is provided with the driving faces 32, as will be best understood by reference to Fig. 3.

34 designates a belt passing around the pulley 27 and also around a pulley 35 mounted on a shaft 36 journaled in brackets 37 which form a part of the main bracket 38 which is secured to the cross-beams 2 in any desired manner. The shaft 36 has mounted thereon a gear 39 which meshes with a gear 40 mounted on a crank shaft 41, which is journaled in brackets 42, which are secured to one of the cross-beams 2. The crank shaft 41 has fixed thereto an adjustable crank disk 43 which consists of a chambered casing having opposite sides near its periphery recessed, as at 45, to receive plates 46, through bne of which passes an adjusting screw 47, which is centered in the other plate, as will be understood by reference to Fig. 6. l

48 designates a collar fixedly secured in any desired manner to the adjusting screw 47 and bearing against the inner face of one of the plates 46, in order to prevent relative longitudinal movement of the adjusting screw with respect to said plates and at the same time permit the rotation of the ad justing screw 47. The outer face of the disk 43 is provided with a slot 49, see Figs. 7 and 8, so that a T-shaped slot is formed at opposite sides ofthe disk to provide for the assembling with respect to said disk of a T-shaped crank pin 50. This crank pin 50 consists of a square or polygonal shaped head 51, from which projects a pin 52 which passes through a crank arm 53 and is secured with respect thereto by means of a nut 54 which bears against a washer 55, which bears against a flanged sleeve 56 mounted on the crank pin 50.

The crank arm 53 has its outer end bifurcated to receive an adjusting collar 57, through which passes a pin 58 which is loose in the crank arm 53,, but fixed with respect to the collar 57 by means of a pin 59. The ends of the pin 58 travel on the guides 60, which are carried by yokes 61.. The adjusting collar 57 is adjusted by means of the set screws 62 and 63 which bear against opposite faces of the adjusting collar 57. The screw 62 is locked in its adjusted position by means of a'lock nut 64, and the screw 63 is locked in its adjusted position by means of a lock nut 65. The arms of the yoke 61'are providedrwith the hubs 66 which are mounted on stud shafts 67, which are fixed by means of set screws 68 in the upper ends of the posts 69, which.

latter are 'adjustably mounted in casings 70 forming a part of the bracket 38.

The casings 70 are split, as indicated at 71, in order to form a split sleeve and are provided with the apertured cars 72, through which pass fastening devices 73, whereby the posts 69 are fixed in their adjusted position. In order to adjust the heights of these posts, set screws '7 4 are provided which are in threaded engagement with flanged nuts secured to the bottom of a casing 70 and adapted to bear against the bottom of the post 69. The post 69, as seen in Fig. 2, is provided with an oifset 77 in which is secured a guide, pin 78, which passes into an aperture 79 in an offset 80 of the casing 7 O, in order to prevent any rotation of the posts 69, during the operation.

The yoke 61 is provided with the hearings or sleeves 81, one of which is split and provided with a fastening device 82, in order to look a sleeve 83 in working position.

84 designates a supporting rod slidable in the sleeve 83, and agalnst the bottom of this rod bears an adjusting screw 85 which is in threaded engagement with the lower end of the sleeve 83. The rod 84 at its upper end is secured to an arm 86, which latter has connected with it the rod 87 which is slidable in apertured bosses 88 carried by the yoke 61. The arm 86 is provided with a lug 89 on which a sleeve 90 has a driving fit.

The top of the supporting rod 84 is slot ted, as indicated at 91, see Fig. 9, in order to receive a key 92, which also fits into a slot in the sleeve of a grinding lap 95. The sleeve 9 1 is slidable upon the upper end of the supporting rod 8 1 and is slidable in the sleeve 90. Interposed between the upper end of a supporting rod 841- and the grinding lap 95 is a spring 96. The upper end of the grinding lap 95 is surrounded by a pan 97 which contains the grinding material.

The belt 34: preferably cooperates with a belt tightener consisting of an adjustably mounted idler pulley 98.

In order to prevent any leakage of the grinding material from the pan around the grinding lap and into the bearing, the pan 97 has the bottom thereof provided with a layer of pitch or other material 98.

The operation of our novel grinding machine for toric lenses will now be readily apparent to those skilled in this art and is as follows:

The lenses are first applied to the lens block and for this purpose they are ordinarily placed into a separate fixture which supports the lenses around the periphery of the lens block and in spaced relationship therefrom. The pitch or other adhesive material is then poured in so as to form the support for the lenses. The lens blocks are then assembled with respect to their block spindles 9 and 41-. The keys are then inserted through the hub of the lens block spindle and through the aperture in the shaft and the set screws which bear against the keys are then tightened, and the machine is ready to be started.

The emery or other grinding material employed is dropped on the periphery the lenses and the machine is started, there by causing rotation of the main driving shaft 1, and owing to the provision of the gears 7 and 8, the rotation of the shaft 9. The grinding laps are yieldingly pressed a a-inst the lenses owing to the provision or the springs 96. During the revolution of the lens blocks, the grinding laps are oscillated, due to the oscillation of the yoke 61 which is effected in the following manner: The belt passing around the pulley 27, the hub of which interlocks with the hub of the set collar 30 fixed to the shaft t, causes the pulley 35 on the shaft 36 to be driven.

Owing to the provision of the gear meshing with the gear 10, the crank shaft 41 will be rotated, thereby I'GClPIOCttlllg the crank arm 53., and the yoke 61 will be oscillated together with the grinding laps which it carries. After the driving shaft 4 has been rotated for a desired interval, its direction of rotation is reversed by any desired or conventional mechanism, such as is well known in the art and which we have theretofore deemed it unnecessary to illustrate such mechanism.

In Fig. 11, we have illustrated a typical and well known type of reversing mechanism wherein the belt 6 passes around a pulley 100 fixed on a shaft 101 journaled in shaft hangers 102. Loosely mounted on the shaft 101 are-two pulleys 103 and 10lwith which are adapted to engage a clutch 105 keyed to the shaft 101 and provided with a clutch collar 106 to which is connected a reversing lever 10?. Around the pulley 10% passes a straight belt driven from a main power shaft (not shown) and around the pulley 103 passes a crossed belt which is also driven from the main power shaft.

When the operator shifts the lever 10? to the left, the clutch 105 will be moved into engagement with the pulley 10 1, which is in driving connection through a straight belt with the main drive shaft (not shown) to impart motion to the shaft 101 on which is secured the pulley 100 carrying the belt 6 in driving connection with the pulley 5 mounted on the shaft 4 carrying one of the lens blocks 12 and the gear 7 which latter is in mesh with the gear 8 on the shaft 9 carrying another lens block 17. When it is desired. to reverse the rotation of these lens blocks, the operator shifts the lever 10? to the right to bring the clutch 105 into engagement with the pulley 103, which is in driving connection through. a cross belt with the main drive shaft (not shown) to cause a reversal of the motion of the shaft 101, consequently reversing the motion of the pulley 100, belt 6, pulley 5, shaft 4-, gears 7 and S, and shaft 9, thereby causing the rotation of the lens blocks 12 andl? in a reverse direction.

The set collar 30 on the main drive shaft is provided with a lug forming segment equal to one-half of its periphery which engages with a lug forming segment on a boss of a loose pulley which is equal to one quarter of its periphery so that the possible amount of lead between the lens block and the pulley with which the collar engages is equal to the difference between the angular value of the driving lug of the collar and the lug of the pulley, which is preferably 90. This lead. which is possessed by the lens block spindle, is only produced when the main drive pulley has its rotation reversed. The function of this lead is to dissynchronize the oscillating action of the grinding lap which is essential for the production of a uniform surface on the lens, since if. the lap followed the same path continually, channels and other conditions would be formed on the lens surface which would produce aberration after the lenses are polished. The grinding laps oscillate preferably six times to each revolution of the lens block and the novel construction of this dis-synchronizer causes the grinding lap to assume a different path when the rotation of the main drive shaft is reversed.

The lead of the new path is preferably v about over that of the old path.

By such change in the paths which takes place several times during one grinding operation on the lenses, a uniform and perfect surface is produced for polishing, so that a high quality surface on the lens after pol ishing is produced.

On the reversing of the direction of rotation of the main driving shaft 4, the driving lug 31 on the set collar 30 will rotate for a desired interval before it comes into contact with the driving lug 28 of the pulley 27, so that the lens blocks are rotated a quarter of a turn before the oscillation of the grinding laps begins again. It will thus be seen that when the grinding laps commence their grinding action again they will be in a different path from that in which they were originally. In other words, the path of the grinding lap has been shifted in respect to its original path, so that upon repeated reversals, the paths overlap and the likelihood of any channels, unevenness, or irregularities being formed in the surface being ground are eliminated. It will thus be seen that we provide automatic means to vary the paths of the grinding laps on the lenses.

The crank disk has the crank pin secured thereto in such a manner that the eccentricity ofthe crank pin may be varied, as desired. The higher the focus of the lens to be ground, the greater must be the eccentricity of the crank pin in order to carry the crank arm through a greater space to provide a longer swing for the oscillating yoke and a uniform surface of the grinding lenses.

We provide novel means for adjusting the machine so that lenses of different foci may be ground. The stud-shafts 67 which support the yokes are adjusted to bring their center line below the horizontal plane of the centers of the spindles for the block lenses, and adjustments are provided in accordance with the focus which it is desired to grind. If the axi of the stud shaft and the axes of the block spindles are in the same horizontal plane, a true sphere would be formed, but as the present machine is especially designed for the grinding of toric lenses, it is necessary to provide an adj ustment so that the cylindrical curve of the lenses may be varied.

The fastening devices 7 3 are loosened, and the lock nuts 76, and the adjusting screws 74 are then operated-to vertically adjust the posts 69 and thereby the stud shafts 67, on which the yoke 61 is swingingly supported.

The adjusting collar 57 is then adjusted by actuation of the set screws 63 and 62 in order to bring the center of the adjusting collar into the same horizontal plane as that of the center of the crank shaft 41. This compensates to produce the same length of stroke on each side of the center of the lenses carried by the lens blocks, so that the same amount of grinding will be efl'ected on each side of the center of each lens.

l Vhen the yoke is set to grind a certain focus, the center line passing through the pin at the forward end of the crank arm, and the center line passing through the shaft on which the crank disk is mounted, should lie in the same horizontal plane to create an equal swing on either side of the centers of the lenses. If the yoke is set to grind some other radius, it shifts the center line of the pin at the forward end of the crank arm to some other position, so that means are provided to bring it back in the same plane with the center line of the crank shaft to compensate for such adjustment.

in order to provide a quick adjustment for the grinding laps with respect to the lens blocks, we provlde novel means for adjusting the grinding laps with respect to the lenses. By the proper actuation of the fastening devices 82, v the sleeves 83 and the grinding laps and their adjuncts may be quickly moved into or out of their operative position. In order to adjust the tension for the different grinding operations, it is simply necessary to actuate the adjusting screw 85 seen in Fig. 5, thereby varying the compression of the springs 96.

The pan affords a constant supply of grinding abrasive, while the machine is operating and on reversal of the rotation of the lens block, it permits the abrasive, which has been deposited in one side of the pan to be drawn between the grinding lap and lens blanks to perform its particular duty, this action taking place each time the lens block reverses, thereby affording a saving in grinding material.

The higher the foci of the lens, the greater the amount of surface that must be ground, and we therefore provide novel means for varying the length of stroke of the oscillating yoke 61. This can readily be'accomplished, as is apparent, by the proper actuation of the adjusting screw 47, see Fig. 6, and thereafter the nut 54 is tightened in order to clamp the crank pin with respect to the crank disk 4:4:-

It will be apparent from the foregoing that we provide novel means for producing a dwell in the operation of the yoke and the grinding laps carried thereby during the grinding operation, and such dwell is automatically produced during the grinding operation.

It will also be apparent that in our present machine, the parts are constructed in such a manner that the cost of manufacture is re duced to a minimum, since many of the parts can be constructed of stock material and the amount of machine work, which it is requisite to do, is reduced to a minimum.

It will also be apparent that we provide novel means for adjusting the machine to grind lenses of different foci.

In so far as we are aware, we are the first in the art to devise a machine of this character, a dis-synchronizer which is automatically actuated, or a compensator or stroke equalizer as disclosed, and it is to be understood that our claims to such features are to be interpreted with corresponding scope.

It will be understood that while in the present instance we have shown one grinding unit only, that in practice a number of these units are carried by the same frame and are under the control of a single oporator, so that while one unit is having the lenses removed or new lenses inserted, the other units will be in operation, thereby enabling one to produce a maximum output with a minimum amount of operating expense.

It will now be apparent that we have devised a novel and useful toric lens grinding machine, which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and while we have, in the present instance, shown and described a typical embodiment thereof which will give in practice satisfactory and reliable results, it is to be understood that the same is susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is

1. In a lens grinding machine, a lens block, a grinding device, and means to actuate said lens block and said grinding device, said actuating means including a driving and a driven member having interlocking lugs with lost motion between their driving faces to cause said grinding device to automatically change its path during the grinding operation.

2. In a lens grinding machine, a driving shaft, lens blocks rotated thereby, a yoke, posts on which said yoke is swingingly supported, means to adjustably support said posts, grinding laps carried by said yoke, and means to operatively connect said yoke with said driving shaft to effect the oscillation of said yoke.

3. In a lens grinding machine, a driving shaft, lens blocks rotated thereby, a yoke, posts on which said yoke is movably mounted, adjusting screws to vertically adjust said posts, means to clamp said posts in their adjusted positions, grinding laps carried by said yoke, and means to operatively connect said yoke with said driving shaft to effect the oscillation of said yoke.

4. In a lens grinding machine, a driving shaft, lens blocks actuated thereby, a yoke, posts on which said yoke is movably mounted, means to adjustably support said posts, grinding laps carried by said yoke, a crank arm, an adjusting collar connected with said crank arm and movably connected with said yoke, means to secure said collar in adjusted position with respect to said yoke, and means to operatively connect said crank arm with said driving shaft.

In a lens grinding machine, a driving shaft, lens blocks actuated thereby, a yoke, posts on which said yoke is movably mounted, means to adjustably support said posts, grinding laps carried by said yoke, a crank arm, an adjusting collar connected with said crank arm and movably connected with said yoke, means to secure said collar in adjusted position with respect to said yoke, and a dis-synchronizer operatively connected with said crank arm and actuated by said driving shaft, said dis-synchronizer including a driving and a driven member having interlocking lugs with lost motion between their driving faces.

6. In a lens grinding machine, a driving shaft, lens blocks actuated thereby, a yoke, posts on which said yoke is movably mounted, means to adjustably support said posts, grinding laps carried by said yoke, a crank arm, an adjusting collar connected with said crank arm and movably connected with said yoke, means to secure said collar in adjusted position with respect to said yoke, a dis-synchronizer operatively connected with said crank arm and actuated by said driving shaft, said dis-synchronizer comprising a hub member having a driving lug forming a segment of a circle and loose on said driving shaft, and also comprising a collar fixed to said shaft and having a driving lug cooperating with the lug on said hub, said lugs having lost motion be tween their driving faces, and means to vary the stroke of said crank arm.

7. In a lens grinding machine, a lens block, a driving shaft connected with said lens block, a set collar fixed to said shaft and having a driving lug, a pulley loosely mounted on said driving shaft and having a driving lug forming a segment of different area than the area of the driving lug of said set collar, a grinding lap mounted to oscillate with respect to said lens block, and means actuated by said pulley to effect the oscillation of said grinding lap.

8. In a lens grinding machine, a lens block, a driving shaft to rotate said lens block, a dis-synchronizer, comprising a driving and driven member having interlocking lugs with lost motion between their driving faces, a yoke oscillated by said dis-synchronizer, a grinding device carried by said yoke, means to adjust said yoke to grind lenses of different foci, and means to compensate for the adjustment of said yoke, so that said grinding device will have an equal swing on each side of the center of the lens block.

9. In a lens grinding machine, a plurality of intergeared lens spindles, lens blocks mounted on said spindles, means to drive one of said spindles, a yoke movably mounted, grinding laps carried by said yoke, and means connecting said yoke and one of said spindles to effect the oscillation of said yoke and to automatically vary the path of said grinding laps when the direction of rotation of the spindles is reversed, said means including a driving and a driven member having interlocking lugs with lost motion between their driving faces.

10. In a lens grinding machine, a framework, posts vertically adjustable in said frame-work, means to secure said posts in their adjusted position, stud shafts fixed in said posts, ayoke having its free ends loosely mounted on said stud shafts, grinding laps carried by said yoke, a crank arm, a driving shaft operatively connected with said crank 7 arm, lens blocks rotated by said driving shaft, and means to adjustably connect said crank arm to said yoke to cause an equal swing of said grinding laps on each side of the center of the lenses in accordance with the focus of the lenses being ground.

11. In a lens grinding machine, lens blocks movably mounted, means to actuate the lens blocks, a yoke, posts on which said yoke is pivotally carried and provided with means to prevent their rotation, adjusting screws carried by said yoke and engaging me s said post, means to clamp said posts in their adjusted position, grinding laps resiliently mounted in said yoke, and means to oscillate said yoke. I i

12. In a lens grinding machine, a lens holder, a grinding device, means to oscillate said grinding device and produce a dwell in such oscillation during the grinding operation, said'meansincluding a driving shaft, a member fixed on said shaft, and a member loose on said shaft, said members having interlocking lugs with lost motion between their driving faces. 7

13. In a lens grinding machine, a lens holder, a yoke pivotally supported, a sleeve adjustably mounted in said yoke, a rod' adjustable in said sleeve, a grinding lap interlocked with said rod to prevent relative rotation, a spring between said rod and grinding lap, and means to oscillate said yoke.

14-. In a lens grinding machine, a frame, a lens carrying block, a driving shaft to actuate said block, means to actuate said driving shaft, and means to reverse the direction of rotation of said driving shaft, a yoke pivotally mounted on said frame, lens grinding devices carried by said yoke, a crank arm connected to said yoke, means to operatively connect said driving shaft with said crank arm to oscillate thelatter, comprising a member fixed to said driving shaft, a second memberloose on said shaft,said members having interlocking lugs with lost motion between their driving faces, whereby a dwell is produced in the rotation of said driving shaft.

RUDOLPH H. BECK. RUDOLPH J. BECK.

lVitnesses: g

H. S. FAIRBANKS, C. D. MOVAY. 

